Title: Globin
Literature References: The colorless, basic protein of hemoglobin. Formed from tissue protein in the body, the globin part of catabolized hemoglobin is re-used (unlike heme, the prosthetic group of hemoglobin). Prepn from ox hemoglobin: Anson, Mirsky, J. Gen. Physiol. 13, 469 (1930). Globin from normal adult human hemoglobin consists of four polypeptide chains: two a-chains and two b-chains. The a-chain contains 141, the b-chain 146 amino acids. Thus globin contains 574 amino acids and has an approx mol wt of 62,000. Abnormal globins may contain g- and d-chains. Structure: Braunitzer et al., Z. Physiol. Chem. 325, 283 (1961); 331, 1 (1963); Konigsberg et al., J. Biol. Chem. 237, 1549, 2547 (1962); 238, 2016, 2028 (1963). Review of prepn and properties: Rossi Fanelli et al., Adv. Protein Chem. 19, 124 (1964). Review: Braunitzer et al., ibid. 1.
Properties: Denatures rapidly above 17°. At pH values near neutrality, combines with ferroprotoporphyrin to yield hemoglobin, or with ferriprotoporphyrin to yield methemoglobin. |